Such angle measuring systems are used to measure rotary motions and rotational positions of a machine part, for instance, a shaft. The rotary motion is determined either incrementally or absolutely; the output measured value, for example, is a sequence of counting pulses, a counter value or a code word. Corresponding angle measuring systems are used particularly in what are referred to as pick-and-place machines in the manufacture of electronic components, or in machine tools for measuring rotary movements. The reproducibility or repeatability of the rotational angles of machine parts precisely to only a few angular seconds is very important when working with pick-and-place machines, for instance. In particular, the absolute accuracy of the measurement results of an angle measuring system is crucial in the case of machine tools. Certain conventional angle measuring systems have a separate bearing assembly of the component parts rotatable relative to each other.
The accuracy of an angle measurement is influenced by the quality of the angle scaling, its eccentricity and by the radial runouts of the bearing assembly or wobble errors.
German Published Patent Application No. 30 36 005 describes a method for producing an angle scaling for an angle measuring system in which code tracks are applied to a code disk by a laser beam. When being written on, the code disk is already connected to a shaft, so that the code disk is already centered relative to the shaft during the writing of the code pattern.
This method has the disadvantage that the angle measuring systems produced by it do not achieve the highest accuracy, are not sufficiently robust for many applications and moreover, require a relatively great amount of space.